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Connect Four Embedded System

This repository contains our project for the INFO2055-1 - Embedded System Project course. The goal was to build a complete embedded system able to physically play Connect Four against a human player.

The project combines several parts: mechanical design, electronics, PCB design, PIC assembly firmware, UART communication, and a C++ program used to compute the bot move.

Repository Structure

• firmware/main/: main PIC assembly firmware for the PIC16F1789 microcontroller.
• firmware/tests/: small test programs used to validate hardware components separately.
• software/connect4solver/: C++ Connect Four solver and serial communication with the embedded system.
• hardware/kicad/: final KiCad PCB project and interactive BOM.
• docs/: tutorial, test PCB image and useful datasheets.

General Behavior

The human player drops a token into a column. Sensors detect the played column, then the PIC sends this information to the C++ program through UART. The solver computes the bot response and sends the column back. The embedded system then moves the mechanism and drops the bot token into the selected column.

The firmware handles, among other things:

• column detection through sensors;
• UART communication;
• stepper motor control;
• limit switch handling;
• mechanism movement logic;
• LED debug signals.

PIC Firmware

The main firmware file is:

firmware/main/main.asm

It targets the following microcontroller:

PIC16F1789

The files in firmware/tests/ were used to test hardware parts separately: motor, pump, laser, servomotor, UART, sensors, etc.

Connect Four Solver

The solver is located in:

software/connect4solver/

Build it with:

cd software/connect4solver
make

Run it with a serial device path:

./c4solver <device_path>

Example:

./c4solver /dev/ttyUSB0

The program listens for moves sent by the PIC, updates the game state, computes the best move and sends back a one-byte encoded response.

Hardware

The hardware/kicad/ folder contains the final KiCad PCB project: schematic, PCB and interactive BOM.

Useful documents are stored in docs/datasheets/, including the PIC16F1789 datasheet and PDF schematics of the PCBs.

Contributions

• Joachim Amandine: tests
• Malaise Romain: the base, state machine of the PIC assembly code and most of the work on the assembly firmware.
• Renard Baptiste: UART communication, C++ program and most of the work on the assembly firmware.
• Schins Martin: all the modeling, the mechanical design, and part of the electronics.

In addition to individual work, we regularly met in person at the lab. Several full days were spent working together on integration, testing and improving the complete system.

Note

This repository is a student project archive. It keeps the final code, intermediate hardware tests, hardware files and useful documentation needed to understand the complete system.